While being chased by a spy Mike is swimming with a large camera in his hand. Next the spy shoots a spear at Mike, but he no longer has the camera. Then as Mike nears the cave he has the camera again, but he is never seen dropping it. All while the spy is pursuing him with an underwater scooter.
When the group is diving, the stranger with the scooter slips off on his own and (in the narration) Mike Nelson says: ". . . he was getting away from us below at an underwater speed of twelve knots per hour." An ex-Navy man such as Mike should know that a "knot" is a "nautical mile per hour" and stands alone when referring to speed. What he said was wrong . . . as if he had said "a hundred miles an hour an hour."